Let's see... I have a copy of the Neverhood for the PC (anyone else played this one?) which is rare enough to fetch about $50 on ebay. I have both the orcarina of time and mujora's mask gold catridges with the case and instruction manual in good shape. I also have a few incredibly obscure import saturn games. One is called Mondou Monogatari, and it's an RPG based off the Puyo Pop series (it's actually pretty fun though I couldn't get to the end due to not being able to read japanese.) The other is Slayers Royal 2, but I don't think this is quite as obscure since there was a PSX version of this as well. Those games are in good shape, but I have no clue if they are actually valuable or not.